Firefox.
> Chrome also came in at slightly lower memory consumption across all the benchmarks with total memory usage on average at 4.67GB to Firefox at 4.83GB.
This is anecdata, of course, take with a pinch of your preferred flavouring powder.
Windows even runs (semi-playably) 2020's shooters in this condition, though you need to kill any windows close to the tab limit that are full of recently opened tabs.
[Yes, I know, the horror]